1. Field of the Invention
The present invention relates to a motor vehicle suspension system comprising an elongate leaf spring which is vertically resilient and extends transversely of a motor vehicle, the leaf spring interconnecting knuckle members of the motor vehicle.
2. Description of the Relevant Art
One known motor vehicle suspension system comprises an elongate, vertically resilient leaf spring that extends in the transverse direction of a motor vehicle. The leaf spring has opposite ends connected to respective laterally spaced knuckle members coupled to axles, respectively, on which road wheels are mounted. It is desirable that the leaf spring be supported in a manner to allow its vertical swinging movement in response to vibration of the road wheels and also to maintain its transverse central axis with respect to the body of the motor vehicle.
Japanese Utility Model Publication No. 53-29291 discloses a suspension system with a transverse leaf spring interconnecting laterally spaced knuckles, the leaf spring being supported on a vehicle body at two laterally spaced points for limited lateral and vertical movement with respect to the vehicle body. Because the lateral movement of the leaf spring is limited, the suspension system has a comparatively high degree of lateral rigidity. However, vertical swinging movement of the leaf spring is also limited since the lateral movement of the leaf spring is limited at the two supporting points. As a result, the function of the transverse leaf spring as a stabilizer is low, making riding comfort poor.
Japanese Laid-Open Patent Publication No. 2-133212 also shows a suspension system with a transverse leaf spring interconnecting laterally spaced knuckles. The leaf spring is supported such that it is allowed to move transversely with respect to a vehicle body, but limited against vertical movement, at two laterally spaced points. The suspension system also includes a mechanism located at its center between the two supporting points for allowing the leaf spring to move vertically, but limiting transverse movement of the leaf spring.
Inasmuch as the vertical movement of the leaf spring is limited at the two laterally spaced points and the transverse movement of the spring spring is limited at its center, the suspension system maintains its transverse rigidity, and the leaf spring is permitted to perform a stabilizer function.
The mechanism for limiting transverse movement of the leaf spring, disclosed in Japanese Laid-Open Patent Publication No. 2-133212, comprises a guide roller disposed on the center of the leaf spring and held in rolling engagement with a guide rail vertically supported on the vehicle body. Since the guide roller and the guide rail are held in contact with each other at all times, they wear due to friction therebetween. Therefore, the mechanism remains to be improved for greater durability.